Black Cherry Aphid
Overwinter as eggs on twigs and fruit spurs; hatch just before bloom. Migrate to mustard family weed hosts during summer.
Curled leaves; copious honeydew can cause severe stickiness on fruit.
Look for shiny black eggs in early spring at the base of buds.
No threshold determined.
Degree Day Model
Delayed dormant oil will usually take care of this aphid. Numerous beneficial insects including lady beetle adults and larvae, lacewing larvae, and syrphid fly larvae help suppress aphid populations.